Azelaic acid can be made by oxidizing oleic acid at the carbon-carbon double bond to form azelaic acid and pelargonic acid as a byproduct. This process can yield azelaic acid at a fairly low price, given the ready availability of oleic acid at commodity prices. The resulting product can end up containing a high amount of pelargonic acid impurity, however. This can result from the relatively close boiling points of azelaic acid and pelargonic acid, which makes it more difficult to remove the pelargonic acid impurity to obtain a pure stream of azelaic acid.
Therefore, there is a continuing need to discover methods that can generate azelaic acid at high yields with an impurity profile that is more desirable that that obtained from the oxidation of oleic acid.
The cross-metathesis of natural oils with a short-chain olefin can provide a means of obtaining chain-shortened unsaturated fatty acids. Examples include 9-decenoic acid. If short-chain olefins besides ethylene are used for the cross-metathesis, other chain-shortened unsaturated fatty acids can result.
The disclosure therefore provides methods of using such chain-shortened unsaturated fatty acids to generate azelaic acid in a manner that offers one or benefits over the oxidation of oleic acid.